STABILIZATION OF BEER

Description

Field of invention

[0001] The present invention relates to the stabilization of beer. State of the art

[0002] At the end of the maturation process, beer contains a multitude of yeast and haze particles, which must be removed for visual reasons and, in particular, for preservation. Filtration removes these haze-causing substances from the beer, resulting in a clear filtrate. Stabilization aims to remove substances from the filtrate that, over time, combine within the bottled container to form turbidity, which becomes visually recognizable as cloudiness once it reaches a certain size. These substances and haze typically consist of protein-tannin compounds.

[0003] The period until cloudiness becomes visible significantly influences the best-before date of bottled beer, which is why beer stabilization to increase shelf life has become widespread. In particular, this involves reducing proteins and / or tannins (polyphenols) in the beer. In the current state of the art, this process involves adding the filtered beer, as it is known in Figure 1 As shown, a stabilizing agent is added volume-proportional (i.e., with a constant mass / volume flow rate) and, after a defined contact distance and corresponding contact time at a filter medium, such as a filter cartridge, filter disc, or slotted screen, is removed from the liquid. Alternatively, the stabilizing agent (e.g., PVPP) can also be added during filtration, in addition to the filter aid (e.g., diatomaceous earth, cellulose, or perlite).

[0004] Figure 1The graph shows the constant mass flow rate of the stabilizing agent or volume flow rate of the stabilizing agent suspension added over time (abscissa), the continuously increasing stabilized beer over time (solid line), and the reduction rate of the turbidity-forming agents (dotted line).

[0005] For tannin-related stabilization, breweries often use polyvinylpolypyrrolidone (PVPP) to reduce the amount of dissolved polyphenols in the filtrate. With the conventional constant volume-proportional dosage of PVPP, the stabilizing effect is based on the contact time between PVPP and the beer to be stabilized within the flow to the filter elements. The stabilizing effect depends on the diffusion of polyphenol molecules to the PVPP particles, since there is (almost) no relative velocity between the stabilizing agent and the beer within the flow. The mass of PVPP used is determined empirically and validated by the minimum shelf life of the stabilized beer. At the end of the contact section, the stabilizing agent is deposited on a filter medium and carried through by the subsequent suspension, causing the filter cake to increase in height.

[0006] In the prior art, however, an excess of stabilizing agent must be added. This is evident, for example, from the fact that part of the stabilizing effect is based on the filter cake already deposited on the filter medium, which is reflected in an increasing stabilization rate during the filter's operating time. If this stabilizing effect were not present as the water flows through the deposited cake, the reduction rate would have to remain constant throughout the entire stabilization process. Based on this finding, it is clear that there are still free binding sites within the deposited filter cake of stabilizing agent for the adsorption of potential haze-causing substances, and therefore the stabilizing agent was added to the beer being stabilized in excess.

[0007] Consequently, a constant volume-proportional dosage (i.e., with a constant mass flow rate) of stabilizing agent results in an unnecessarily high consumption of this agent. This leads to unnecessarily high costs for the use of the stabilizing agent and also to a reduction in the maximum service life of a filter, as the maximum cake height is reached sooner than necessary.

[0008] US Patent 2014 / 004237 A1 describes a method for stabilizing beer using two or three filters operated in series or parallel. Beer to be stabilized is fed to a first filter to pretreat the stabilizing agent. The partially stabilized beer (which therefore has a lower concentration of stabilizing agent) is then fed to a second filter, where pretreatment of the stabilizing agent has already been completed, for final stabilization. US Patent 2019 / 002669 A1 describes a method for clarifying liquids using cellulose fibers.

[0009] WO 2016 / 169924 A1 describes a method for beer stabilization in which the dosage of a stabilizing agent is determined based on the polyphenol content measured during the stabilization process. However, this requires a relatively complex setup for measuring / determining the polyphenol content and corresponding control of the mass flow rate of the stabilizing agent.

[0010] The present invention therefore aims to provide a method for stabilizing beer that allows for more efficient and cost-effective stabilization than is possible in the prior art. Description of the invention

[0011] The above-mentioned task is solved by a beer stabilization process which includes the steps of feeding a batch (production unit) of beer to be stabilized to a filter medium over a period of time consisting of a plurality of time intervals, and dosing a stabilizing agent to the beer to be stabilized within the period of time in order to remove haze-forming substances from the beer to be stabilized.The stabilizing agent (for the batch) is dosed using a regulated or controlled dosing pump according to a predetermined dosing schedule (dosing program) such that, in at least two time intervals of the majority of time intervals, the stabilizing agent is added at a different mass flow rate (here and subsequently, mass flow rate of a stabilizing agent is to be understood as the mass flow rate of a stabilizing agent or the volume flow rate of a stabilizing agent suspension). The dosing schedule is time-dependent and independent of the concentration of the haze-forming agents in the beer being stabilized. The filter medium is part of a filtration system. The filtration system can be a precoat filter.The filter medium can, for example, be or comprise a filter cartridge of a precoat filter. The dosage schedule specifies the dosage as a function of time and independently of (a measurement of) the concentration of haze-forming substances in the batch of beer to be stabilized, which may vary over time.

[0012] The batch can correspond to a quantity that can be held in a provided pressure tank after stabilization. The dynamic dosing of the stabilizing agent according to the invention, based on the dosing scheme, allows for uniform stabilization throughout the entire stabilization process. Compared to the prior art, this reduces the total quantity required to stabilize a batch of beer and / or the equipment required. Likewise, the service life of the filter used for stabilization can be extended and / or the size of this filter can advantageously be reduced compared to the prior art. The dosing scheme is predetermined and, in particular, is not based on current measurements of the concentration of the stabilizing agent or of the turbidity-forming substances to be removed by the stabilizing agent, such as proteins or polyphenols.Polyvinylpolypyrrolidone (PVPP) can be used as a stabilizing agent, for example. Other stabilizing agents that can be used include polyvinylpyrrolidone (PVP), polyamide powder, gelatin, bentonite, tannin, silica gel, and silica sol.

[0013] For example, the entire volume of beer to be stabilized can be passed through a filter unit encompassing the filter medium. According to this example, for a predetermined quantity of beer to be stabilized, no subset of the volume to be stabilized is diverted around the filter unit.

[0014] Since the stabilizing effect is based on the flow through the cake, the flow rate can be increased accordingly so that the filter cake can be permeated with a conduit velocity of the beer to be stabilized in the range of 0.13 - 1.4 mm / s.

[0015] The dosage scheme can specify the mass flow rate of the added stabilizing agent, for example, solely based on a) the time within the specified period and / or b) the (measured) stabilized volume of the beer to be stabilized (i.e., the volume of beer already stabilized during the stabilization process). The exact dosage scheme may vary depending on the choice of filter medium and / or the type of beer to be stabilized.

[0016] In particular, it can prove advantageous to use a relatively higher concentration of the stabilizing agent at the beginning of the stabilization process for the batch of beer to be stabilized, and a relatively lower concentration at a later time. Thus, according to a further development, the stabilizing agent can be added at a first mass rate in a first time interval of the majority of time intervals, especially at the beginning of the period, and in a second time interval of the majority of time intervals, which follows the first time interval (immediately or not immediately) within the period, the stabilizing agent can be added at a second mass rate that is smaller than the first mass rate.

[0017] For example, in a third time interval, which lies between the first and second time intervals, no stabilizing agent can be added. Thus, in the first phase of beer stabilization, a relatively large amount of stabilizing agent per unit of time can be added to the beer being stabilized, allowing for the initial flow of the filter medium. The amount of stabilizing agent can be chosen such that sufficient stabilization of the beer passing through the filter medium occurs over a specific time interval (the aforementioned third time interval) during which no further stabilizing agent is added. In other words, during this (third) time interval, stabilization occurs solely through the flow of the beer being stabilized through the filter cake forming on the filter medium.Following this (third) time interval, stabilizing agent is added again, but at a reduced dosage compared to the initial stabilization process. By efficiently utilizing stabilization during passage through the filter cake, the total dosage during the stabilization period of the batch of beer being stabilized can be significantly reduced compared to a constant volume-proportional dosage of stabilizing agent.

[0018] According to an alternative refinement of the beer stabilization process, the stabilizing agent is added alternately at the first mass flow rate and the second mass flow rate over at least a portion of the majority of time intervals, in each adjacent time interval. For example, in a first time interval, the stabilizing agent can be added at a specific first mass flow rate; in an immediately adjacent second time interval, the stabilizing agent can be added at a second mass flow rate that is only a fraction (approximately between one-fifth and one-half) of the specified first mass flow rate; in a third time interval immediately adjacent to the second, the stabilizing agent can again be added at the first mass flow rate; and in a fourth time interval immediately adjacent to the third, the stabilizing agent can again be added at the second mass flow rate, and so on.

[0019] According to a further development process, the stabilizing agent is added over at least a portion of the majority of time intervals with a decreasing mass flow rate from one interval to the next. The dosage can be continuously / steadily decreasing or achieved through decreasing plateaus in the concentration or mass flow rate of the stabilizing agent, thus counteracting the increasing reduction rate of haze-forming substances during the stabilization process. This allows for both uniform stabilization throughout the beer stabilization process and a reduction in the total amount of stabilizing agent required for the batch.

[0020] While some technical and patent literature does not strictly distinguish between filtering and stabilizing mature beer, here we consider filtration and stabilization separately. Different filter aids and stabilizing agents can be used for filtration and stabilization, for example, diatomaceous earth for filtration and PVPP for stabilization. It should be noted that there are also combined filter aids that serve both filtration and stabilization, such as Crosspure. However, in the present invention, according to certain embodiments, only pure stabilizing agents are used, and not combined filter aids that serve both filtration and stabilization.For example, in the precoat filtration of beer, particles are separated both on the surface of the filter cake and in its depths. Therefore, to prevent surface clogging, filter aids must be continuously added to maintain the filter cake's sieving effect. In contrast, during beer stabilization, only dissolved molecules are adsorbed onto stabilizing agents after the beer has already been filtered to remove the particulate turbidity. This means that the components of the beer that are to be removed by stabilization could not be removed by filtration. Therefore, the number of free binding sites for the adsorptive removal of, for example, polyphenols in the filter cake is crucial, and the sieving effect of the filter cake is less important.

[0021] This document also provides a method for treating beer that includes the steps of one of the beer stabilization methods described above and filtering the beer to be stabilized before introducing the batch of beer to be stabilized into the filter medium. Alternatively, a beer treatment method is provided that includes the steps of one of the beer stabilization methods described above and filtering the beer to be stabilized using the filter medium. Filtration can therefore be carried out either in a filter prior to stabilization or using the same filter / filter medium used for stabilization.

[0022] Furthermore, the above-mentioned task is solved by providing a beer production plant that includes a filter with a filter medium (for example, a precoat candle filter with a filter candle), a dosing pump and a control / regulation device.The control / regulating device is designed to control or regulate the feeding of a batch of beer to be stabilized to the filter medium over a period of time consisting of a plurality of time intervals; to control or regulate the dosing pump for dosing a stabilizing agent to the beer to be stabilized within the period of time in order to remove haze-forming substances from the beer to be stabilized; and to control or regulate the dosing pump according to a predetermined dosing scheme such that the dosing of the stabilizing agent is carried out in such a way that in at least two time intervals of the plurality of time intervals, the stabilizing agent is dosed with a different mass flow rate, irrespective of the quantity of haze-forming substances present in the beer to be stabilized in the at least two time intervals, wherein the dosing scheme is time-dependent and independent of the concentration of haze-forming substances in the beer to be stabilized.For example, the control / regulating device can regulate the dosage of the stabilizing agent by means of a dosing pump depending on the volume of the (already) stabilized beer.

[0023] In the following, embodiments of a method according to the invention are described with reference to the figures. The described embodiments are to be regarded in every respect as merely illustrative and not as limiting, and various combinations of the features mentioned are included in the invention. Figure 1 illustrates relevant parameters of a beer stabilization process based on a conventional constant volume-proportional dosage of a stabilizing agent. Figure 2 illustrates relevant parameters of a beer stabilization process according to an embodiment of the present invention. Figure 3illustrates relevant parameters of a beer stabilization process according to a further embodiment of the present invention. Figure 4 illustrates relevant parameters of a beer stabilization process according to a further embodiment of the present invention. Figure 5 illustrates components of a beer production plant according to an embodiment of the present invention.

[0024] According to the invention, beer is stabilized based on a dosage scheme whereby a variable amount of a stabilizing agent is added to the beer to be stabilized per unit of time during the stabilization process. Such a dosage scheme makes it possible to reduce the amount of stabilizing agent required for a batch of beer compared to the prior art, thus enabling longer residence times and / or smaller filter devices for stabilization than are known in the prior art. Because the stabilizing effect is due to the flow through the filter cake and not due to the contact time, the filter vessel size, which defines the total residence time until the agent is deposited on the candles, can be reduced.In particular, the amount of reduced turbidity-forming agents per unit of stabilizing agent used can be increased compared to the prior art, without overstabilization (unnecessary dosage of unused stabilizing agent). The aforementioned advantages can be realized particularly with the help of the methods described in the [references / documents]. Figures 2 to 4 The illustrated dosage regimens can be achieved.

[0025] The beer to be stabilized is passed through a filter medium (for example, a filter cartridge). A stabilizing agent is dynamically added to the beer. The stabilizing agent can be polyvinylpolypyrrolidone (PVPP) or contain it. Other stabilizing agents that can be used include polyvinylpyrrolidone (PVP), polyamide powder, gelatin, bentonite, tannin, silica gel, and silica sol.

[0026] For example, at the beginning of the stabilization process for a batch of beer, a relatively large amount (per unit of time) of stabilizing agent can be added, and as the stabilization process progresses, the amount (per unit of time) of stabilizing agent added can be reduced. Various dynamic dosing schemes (dosing programs) are described in the Figures 2 to 4 A plant 10 for beer production, in which these dosage schemes can be implemented, is shown schematically in Figure 5 shown.

[0027] According to one embodiment of the inventive method for beer stabilization, beer to be stabilized is first fed from the storage cellar to a filter device 11 of the plant 10 for beer production (see Figure 5The filter unit 11 can be a precoat filter, for example with filter cartridges, filter discs or filter plates as the filter medium, as well as a membrane filter (for example a crossflow filter). Diatomaceous earth, for example, can serve as a filter aid for precoat filtration; it is added to the beer to be filtered (and stabilized) before it enters the filter unit 11. A filter cake forms on the filter medium (for example, filter cartridges) of the filter unit 11, through which the beer is filtered. The filtrate (the filtered beer, largely free of turbidity substances and still requiring stabilization) is discharged from the filter unit 11 and transferred to a Figure 5 The optional buffer tank (or an optional expansion vessel) 12 shown is introduced. The filter cake can be permeated with the beer to be stabilized at a flow rate of 0.13 - 1.4 mm / s.

[0028] From the optional buffer tank 12, the filtered beer, which still requires stabilization, is transferred to a further filtration unit 13, where beer stabilization takes place, reducing haze-causing substances such as polyphenols and proteins. For beer stabilization, a stabilizing agent (e.g., PVPP) is added to the beer. For example, the stabilizing agent can be added to line L, through which the beer to be stabilized is introduced into the filtration unit 13. The time-dependent dosing of the stabilizing agent can be achieved using a controllable or adjustable dosing pump 14.

[0029] Although it was mentioned that the beer is fed from the storage cellar to the filtration process, the beer could also originate from the fermentation cellar, for example. Filtering the beer is merely optional; the beer can also be fed directly from the fermentation and / or storage cellar to the beer stabilization process, i.e., without filtration.

[0030] The filter device 13 used for beer stabilization can be a precoat filter with filter candles as the filter medium. A filter cake forms on the filter medium (e.g., filter candles) of the filter device 13, which stabilizes the beer. Due to the dynamic dosing of the stabilizing agent according to the invention, more binding sites can be utilized during the flow through the filter cake than with a constant volume-proportional dosage. This allows the amount of reduced haze-forming substances per unit of stabilizing agent used to be increased compared to the prior art. According to an alternative embodiment, filtration and stabilization can be carried out in one and the same filter device using a filter aid and a stabilizing agent.

[0031] According to one embodiment, the entire volume of the batch of beer to be stabilized is passed through the filter device 13 without any part of the volume being diverted around the filter device 13 for subsequent blending with the stabilized beer (via a bypass line).

[0032] The stabilized beer is discharged from filter unit 13 and transferred to a container in Figure 5The beer is introduced into the pressure tank / buffer tank 15 shown, from which it can be supplied for bottling. Filtration and stabilization of the beer can be carried out by a control unit 16 of the beer production system 10. In particular, the control unit 16 can control or regulate the operation of the dosing pump 14 according to a predetermined dosing schedule, for example, controlling the operation of the dosing pump 14 over the duration of the stabilization of a batch. The dosing schedule determines the dosage of the stabilizing agent for a batch of beer to be stabilized (which is determined by the capacity of the pressure tank) that can be received by the pressure tank / buffer tank 15 after stabilization.

[0033] For example, the control unit 16 can control the operation of the dosing pump 14 according to a time schedule or depending on the time-dependent volume of the stabilized beer. According to the invention, the dosing pump 14 is not controlled based on a measured concentration of turbidity-forming agents. When the pressure tank 15 is filled with the stabilized beer, another batch (the size of which is determined by the capacity of the additional pressure tank) can be stabilized for another pressure tank according to the dosing schedule. The available operating time of the filter unit 13 for beer stabilization allows, for example, the stabilization of four or five batches of beer and thus the filling of four or five pressure tanks with stabilized beer.

[0034] In the Figures 2 to 4According to various embodiments of the invention, relevant parameters for dosage schemes for the stabilizing agent, which enable overall uniform beer stabilization throughout the stabilization process, are shown. During the stabilization period, different reduction rates of the haze-forming agents may occur at different time intervals; however, the overall stabilizing effect largely evens out across the batch and thus within the pressure tank. Time is plotted on the abscissa, and the relevant parameters are the volume of the stabilized beer, the reduction rate of the haze-forming agents, and the mass flow rate of the stabilizing agent used, or the volume flow rate in the case of a stabilizing agent used in the form of a suspension.The dosage schemes are used, for example, to stabilize a batch of beer to be stabilized, to fill a pressure tank with stabilized beer, and subsequently for the next batch.

[0035] According to the in Figure 2In the illustrated embodiment, a relatively high dosage of the stabilizing agent is added during an initial phase (within an initial time interval) of stabilizing a batch of beer. This dosage is achieved, for example, by pre-coating the stabilizing agent on a filter medium of a precoat filter (e.g., a candle filter, horizontal filter, or frame filter). Such pre-coating can take place, for example, for 5 to 15 minutes. The amount of stabilizing agent added during this initial phase of beer stabilization is selected such that, for a specific time interval (e.g., 1 to 2 hours), the desired stabilization is achieved without further addition of the stabilizing agent, simply by the beer flowing through the filter cake coated on the filter medium.After this specific time interval, a further, particularly constant, dosage of the stabilizing agent can be added until the end of the stabilization process for the batch of beer being stabilized, at a significantly reduced mass / volume flow rate compared to the initial stabilization phase. For example, if a pre-treatment with approximately 800 g / m² of stabilizing agent was initiated and no further stabilizing agent was added after the specified time interval, a dosage of approximately 30 g / hl of stabilizing agent can be added. Throughout the entire stabilization process, a relatively uniform reduction rate of the haze-forming substances, for example, approximately 30%, can be achieved, and overstabilization can be avoided.

[0036] According to the in Figure 3In the illustrated embodiment, the dosing scheme alternates between relatively high and relatively low dosage intervals throughout the stabilization process of the batch of beer being stabilized. Within a time period (indicated by the vertical markings of the abscissa) of, for example, 1 hour, a relatively low dosage interval is followed by a relatively high dosage interval. For example, 80% of the total stabilizing agent dosed during the time period can be administered during the relatively high dosage interval, and 20% during the relatively low dosage interval. The time intervals can be adjusted according to the filter hour capacity of the filtration unit used for stabilization (for example, the one shown in the diagram). Figure 5 filter device 13 shown) and / or the capacity of the pressure tank that holds the stabilized beer (for example, the one in Figure 5The pressure tanks shown (15) can be selected. Over the duration of the batch stabilization process, which comprises several time periods (and thus time intervals), a relatively uniform reduction rate of the turbidity-forming agents can be achieved.

[0037] According to the in Figure 4 In the embodiment shown, the stabilizing agent is dosed over the duration of the stabilization process of a batch of beer to be stabilized in a plurality of time intervals, within each of which a constant mass / volume flow rate of the added stabilizing agent is set, wherein the mass / volume flow rate decreases from time interval to time interval during the course of the stabilization process, i.e., over the duration of the process. The first plateau of the Figure 4The mass / volume flow rate of the added stabilizing agent shown is therefore the highest, and the last plateau is the lowest. This counteracts the increasing reduction rate of the turbidity-forming agents (see Figure 1) that occurs over time in the prior art.

Claims

1. Method for stabilizing beer, comprising feeding a batch of beer to be stabilized to a filtering means over a period of time consisting of a plurality of time intervals; and dosing a stabilizing agent into the beer to be stabilized within said time period to remove turbidity-causing substances from the beer to be stabilized; and wherein the dosing of the stabilizing agent is performed by means of a dosing pump (14) regulated or controlled according to a predetermined dosing scheme such that, in at least two of the plurality of time intervals, the stabilizing agent is dosed at a different mass flow rate regardless of the amount of turbidity-causing substances present in the beer to be stabilized during those at least two time intervals, wherein the dosing schedule is time-dependent and independent of the concentration of the turbidity-causing substances in the beer to be stabilized.

2. The method according to claim 1, in which, in a first time interval of the plurality of time intervals, in particular at the beginning of the time period, the stabilizing agent is dosed at a first mass flow rate, and in a second time interval of the plurality of time intervals, which follows the first time interval within the time period, the stabilizing agent is dosed at a second mass flow rate that is smaller than the first mass flow rate.

3. The method according to claim 2, in which, during a third time interval of the plurality of time intervals, which lies between the first time interval and the second time interval, no stabilizing agent is dosed.

4. The method according to claim 2, in which, over at least a portion of the plurality of time intervals, the stabilizing agent is alternately dosed at the first mass flow rate and the second mass flow rate in adjacent time intervals.

5. The method according to claim 2, in which, over at least a portion of the plurality of time intervals, the stabilizing agent is dosed at a mass flow rate that decreases from one time interval to the next over the course of the time period.

6. The method according to any of the preceding claims, wherein the dosing scheme specifies the mass flow rate of the added stabilizing agent as a function exclusively of a) the time within the time period and / or b) the stabilized volume of the beer to be stabilized.

7. Method for treating beer comprising the steps of the method according to any one of the preceding claims and filtering the beer to be stabilized before feeding the batch of beer to be stabilized to the filter medium.

8. A method for treating beer comprising the steps of the method according to any one of claims 1 through 6 and filtering the beer to be stabilized using the filter medium.

9. The method according to any of the preceding claims, in which the filter medium is part of a pre-coating filter and, in particular, is or comprises a filter cartridge of a pre-coating cartridge filter.

10. The method according to any of the preceding claims, in which the stabilizing agent is or comprises polyvinylpolypyrrolidone.

11. The method according to any of the preceding claims, wherein the entire volume of the batch to be stabilized is passed through a filter device (13) comprising the filter medium.

12. A beer production plant (10) comprising a filter device (13) with a filter medium, a dosing pump (14); and a control / regulation device (16) configured to control or regulate the feeding of a batch of beer to be stabilized to the filter medium over a period of time consisting of a plurality of time intervals; to control or regulate the dosing pump (14) for dosing a stabilizing agent into the beer to be stabilized within the time period in order to remove turbidity-causing substances from the beer to be stabilized; and to control or regulate the dosing pump (14) according to a predetermined dosing scheme such that the dosing of the stabilizing agent occurs in such a way in at least two of the plurality of time intervals, the stabilizing agent is dosed at a different mass flow rate, regardless of the amount of turbidity-causing substances present in the beer to be stabilized during those at least two time intervals, wherein the dosing schedule is time-dependent and independent of the concentration of the turbidity-causing substances in the beer to be stabilized.